HDU1174+三维点到直线距离

点B到直线AC的距离 就是 |AB X AC|/|AC|   ‘X’是叉乘   ’ || ‘表示模

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 1 /*
 2 三维+点到直线的距离
 3 */
 4 #include<stdio.h>
 5 #include<string.h>
 6 #include<stdlib.h>
 7 #include<algorithm>
 8 #include<iostream>
 9 #include<queue>
10 //#include<map>
11 #include<math.h>
12 using namespace std;
13 typedef long long ll;
14 //typedef __int64 int64;
15 const int maxn = 105;
16 const int inf = 0x7fffffff;
17 const double pi=acos(-1.0);
18 const double eps = 1e-8;
19 struct point {
20     double x,y,z;
21 };
22 struct line{
23     double a,b,c,d;
24 };//ax+by+cz+d=0;
25 struct people{
26     double hi,r,x,y,z;
27 };
28 double fpow( double x ){
29     return x*x;
30 }
31 int main(){
32     int ca;
33     scanf("%d",&ca);
34     while( ca-- ){
35         people police,thief;
36         point new_one,new_two;
37         scanf("%lf%lf%lf%lf%lf",&thief.hi,&thief.r,&thief.x,&thief.y,&thief.z);
38         scanf("%lf%lf%lf%lf%lf%lf%lf%lf",&police.hi,&police.r,&police.x,&police.y,&police.z,&new_two.x,&new_two.y,&new_two.z);
39         
40         thief.z = thief.z+thief.hi-thief.r ;
41         police.z = police.z+0.9*police.hi-police.r ;
42         new_one.x = thief.x - police.x;
43         new_one.y = thief.y - police.y;
44         new_one.z = thief.z - police.z;//警察与小偷之间的向量
45         double tmp0,tmp1,tmp2;
46         tmp0=new_one.y*new_two.z-new_one.z*new_two.y;
47         tmp1=-new_one.x*new_two.z+new_one.z*new_two.x;
48         tmp2=new_one.x*new_two.y-new_one.y*new_two.x;
49         double sum;
50         sum = sqrt( fpow(tmp0)+fpow(tmp1)+fpow(tmp2) );
51         double ans;
52         ans = sum/sqrt(fpow(new_two.x)+fpow(new_two.y)+fpow(new_two.x));
53         //printf("%lf %lf\n",ans,thief.r);
54         if( ans<=thief.r && (new_one.x*new_two.x+new_one.y*new_two.y+new_one.z*new_two.z)>0 )
55             printf("YES\n");
56         else
57             printf("NO\n");
58     }
59     return 0;
60 }

 

 

posted @ 2013-03-19 21:52  xxx0624  阅读(685)  评论(0)  编辑  收藏  举报